<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <!-- 内嵌式 -->
    <script>
        //alert('沙漠骆驼');
    </script>
    <!-- 外部式 -->
    <script src="Demo1_3.js"></script>
</head>
<body>
    <!--行内式-->
    <input type = "button" value = "按钮1" onclick = "alert('点击了按钮1')">
</body>
</html>